Double coated tapes (or double coated adhesive tapes) have been effectively used for adhesion of component parts during manufacture of electronic products such as televisions, In recent years, performance and quality of such electronic products have increased and products with much thinner bezels are becoming increasingly preferred, thus requiring a double coated tape used to attach a liquid crystal display (LCD) panel to a guide frame to have very strong adhesivity. A cross section of a structure system in which an LCD panel 20 is attached to a guide frame 30 using a double coated tape 10 is shown in FIG. 1.
Also, when the double coated tape used for attachment of the LCD panel hardens, stress is transferred directly to the LCD and compromising the arrangement of the LCD, thereby causing light leakage (a situation in which an LCD screen becomes splotchy). As a result, double coated tapes including a substrate formed of foam (i.e., a foam carrier) having porosity in addition to a substrate formed of a film (i.e., a film carrier) are currently being used. Since the foam substrate is formed of a soft material rather than a stiff material, a double coated tape including the foam substrate may effectively prevent light leakage in LCD panels. A cross-sectional view of a conventional double coated tape including the foam substrate is shown in FIG. 2. The conventional double coated tape as shown in FIG. 2 includes a composite substrate including a film carrier layer 1 and a foam carrier layer 2, and first and second adhesive layers 3 and 3′ formed at both surfaces of the composite substrate, all of which are stacked.
Meanwhile, when defective products formed during a process of manufacturing such an electronic product are discarded, problems including not only resource consumption and environmental pollution but also an increase in economic loss are encountered. Therefore, the defective products should be classified and reused (recycled) according to the constituent elements for the sake of cutting costs for consumers.
In particular, another reason for which LCD panels should be classified and recycled when they are inferior in quality is that they are very expensive. Nevertheless, since an adhesive of the double coated tape has strong adhesive strength and poor foam carrier characteristics, the adhesive of the double coated tape, when removed, is not completely removed cleanly from a surface of the LCD panel, which makes it impossible to reuse (recycle) the LCD panel.
Therefore, many attempts are being made to cleanly remove the adhesive of the attached double coated tape from the surface of the LCD panel including varying the shear strengths to the first adhesive layer and the second adhesive layer disposed at both surfaces of the double coated tape. However, no double coated tapes exhibiting sufficient physical properties to provide reworkability and prevent light leakage have been presented so far.